What does it mean?
P1476 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: EVAP Emission Control LDP Circuit Malfunction/Insufficient Vacuum .
Symptoms
- MIL on
- EVAP monitor fails or never completes
- Possible fuel vapour smell near the rear of the vehicle
- No steady pumping sound during the leak test
- Slightly unstable idle if a genuine vacuum leak is present
Likely causes
- Cracked, collapsed or disconnected vacuum hose feeding the leak detection pump
- Restricted or blocked vacuum supply line
- Failed vacuum solenoid inside the pump assembly
- Leaking diaphragm inside the pump, so it never reaches full stroke
- Weak engine vacuum caused by an intake leak or another engine fault
- Clogged canister filter or restricted vent path adding resistance to the system
- Hoses wrongly routed or swapped after previous service
How to fix it
- Inspect every vacuum hose at the pump for cracks, kinks and disconnection
- Apply a hand vacuum pump to the pump vacuum port and check that it holds
- Verify engine vacuum at idle is within the normal range
- Command the pump with a scan tool and listen for a steady stroking action
- Check the canister filter and vent path for restriction and debris
- Replace deteriorated hoses, and replace the pump if the diaphragm leaks
- Clear the code and run the EVAP monitor to confirm the repair